A bell outline standing for alerts and their settings.
A bell marks where notifications are collected or configured. A bell drawn with a stroke through it means notifications are silenced, which is the more useful half of the convention.
Marks the place where alerts are listed, or the control that turns them on and off.
Contexts: Software
Drawn with a diagonal stroke through it, the same bell means alerts are suppressed — the general negation convention applied to an interface icon.
Contexts: Software
A dome shape with a flared open base and a small dot beneath it for the clapper, topped by a short loop.
Both are used in software contexts.